Why optimization ensures scalability in Power BI - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the DAX formula to calculate total sales.

Power BI

Total Sales = SUM([1])

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ASales[Amount]

BProducts[Category]

CCustomers[Name]

DSales[Date]

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing a non-numeric column like Date or Name.

The SUM function adds all values in the Sales[Amount] column, giving total sales.

2fill in blank

medium

Complete the DAX formula to calculate average sales per customer.

Power BI

Average Sales = DIVIDE(SUM(Sales[Amount]), [1])

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ASUM(Sales[Amount])

BDISTINCTCOUNT(Sales[CustomerID])

CCOUNT(Sales[Amount])

DCOUNTROWS(Customers)

Attempts:

3 left

💡 Hint

Common Mistakes

Using COUNTROWS(Customers) which might not match sales data.

DISTINCTCOUNT(Sales[CustomerID]) counts unique customers, so dividing total sales by this gives average sales per customer.

3fill in blank

hard

Fix the error in this DAX formula to calculate sales growth percentage.

Power BI

Sales Growth % = DIVIDE(SUM(Sales[Amount]) [1] SUM(PreviousSales[Amount]), SUM(PreviousSales[Amount]))

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A-

B+

C*

D/

Attempts:

3 left

💡 Hint

Common Mistakes

Using + instead of - which adds values instead of finding difference.

The formula subtracts last year's sales from this year's sales. The minus sign - is needed to find the difference.

4fill in blank

hard

Fill both blanks to create a measure that filters sales for the current year only.

Power BI

Current Year Sales = CALCULATE(SUM(Sales[Amount]), [1](Sales, YEAR(Sales[Date]) = YEAR([2]())))

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AFILTER

BYEAR

DNOW

Attempts:

3 left

💡 Hint

Common Mistakes

Using YEAR twice without NOW(), or using wrong filter function.

FILTER applies a condition to the Sales table, and NOW() returns the current date. Using YEAR(NOW()) gets the current year to filter sales.

5fill in blank

hard

Fill all three blanks to create a measure that calculates the percentage of total sales for each product category.

Power BI

Category Sales % = [1](SUM(Sales[Amount]), CALCULATE(SUM(Sales[Amount]), ALL([2])), [3]) * 100

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ASales[Category]

B0

CIFERROR

DProducts[Category]

Attempts:

3 left

💡 Hint

Common Mistakes

Using Sales[Category] instead of Products[Category], or missing error handling.

ALL(Products[Category]) removes filters to get total sales. IFERROR handles division errors by returning 0 if error occurs.